The proposed project is an epidemiological study of mental disorder among prison inmates. A sample of inmates will be interviewed using a modified version of the Diagnostic Interview Schedule (DIS) to estimate the prevalence of selected categories of mental disorder. The epidemiological data will be useful for developing strategies to deal with mental disorder among prison inmates. This proposed survey will also complement the community mental health surveys being conducted under the Epidemiological Catchment Area (ECA) Program of the National Institute of Mental Health (NIMH); the proposed survey covers an institutional population and a population which includes a disproportionate number of the kind of individuals most likely to be missed in ECA dommunity surveys. Three major questions will be addressed by the proposed research: What is the prevalence of mental health problems among persons as they enter prisons? What is the impact of an inmate's mental disorder on his prison stay? What is the impact of prison stay on an inmate's mental health? It is likely that mental disorder will be related to length of stay in prison and to aspects of the incarceration like custody classification, institutional infractions and disciplinary actions, victimization, and participation in treatment and educational programs. These relationships will be examined in terms of diagnosis by the DIS at intake and in terms of change in DIS diagnosis 6 and 18 months later. Two major methodological issues will also be addressed by the proposed research. Epidemiological findings from the ECA program and the proposed research will be compared and contrasted. Second, DIS findings will be compared to findings of the MMPI for the surveyed inmates. The MMPI is routinely administered to all those entering prison. Comparison of DIS and MMPI findings for the same group of individuals will provide an opportunity to evaluate the DIs and will also aid in the substantive interpretation of findings. The proposed research will be conducted by the Research Triangle Institute with the close cooperation and participation of the North Carolina Department of Correction.